JP2009046073A - Vehicular front side frame and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the manufacturing cost of front side members by using a common die for the front side members whose length in the longitudinal direction of a vehicle body is varied according to vehicle length. <P>SOLUTION: In the production of many kinds of the front side members in which at least the vehicle body front side of an impact crush area Ba (Bb) set up at a position of the vehicle front side is press-molded into the same cross section shape with a die and the length in the longitudinal direction of the vehicle body of the same cross-sectional shape parts 33, 34 of the impact crush area is varied according to vehicle length, the die is prepared which is used for press-molding the front side frames 11, 12 of the longer one (Cb) of the length in the longitudinal direction of a vehicle body of the same cross-sectional shape parts 33, 34. The die is used for press-molding both of the front side frames having the longer (Cb) and shorter (Ca) same cross-sectional shape parts 33, 34 in the longitudinal direction of the vehicle body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle front side frame and a method for manufacturing the same, and more particularly to a front side frame used in a monocoque automobile.

  An automobile body of a monocoque structure is configured by joining a number of body panels and skeleton strength members made of press-formed steel plates by spot welding or the like (for example, see Patent Document 1).

  As the skeleton structure of the floor part of this type of vehicle body, left and right front side members extending in the longitudinal direction of the vehicle body from the engine room to the dashboard lower panel, left and right side sill members arranged on the left and right sides of the floor panel, and the dashboard lower panel A front floor cross member that is joined and extends in the left-right direction of the vehicle body, a middle floor cross member that is arranged at the rear of the vehicle body from the front floor cross member and that is joined to the left and right side sill members, and is arranged in the front-rear direction of the vehicle body Some of them are composed of left and right floor frames that connect the floor cross member and the middle floor cross member.

  In an automobile having such a skeleton structure, the front side member receives impact loads of frontal collision and offset collision, is press-molded into a groove-shaped section, and a back plate is joined to the groove opening side of the groove-shaped section. It has a skeleton structure with a box-shaped cross-sectional structure.

  The front side member is of the vehicle length determined by the vehicle type and specifications, the vehicle body longitudinal length according to the design, the plate thickness, and the shape. For those with a long vehicle length, the vehicle longitudinal direction length is long and the vehicle length is For short items, the length in the longitudinal direction of the vehicle is short.

  Such a front side member is manufactured by preparing a dedicated press die for each vehicle body longitudinal length, plate thickness, and shape, and press molding with the dedicated press die.

As a method for manufacturing the chassis frame side member, the side member is divided into a plurality of parts in the longitudinal direction (the longitudinal direction of the vehicle body), press-molded in divided units, and the left and right side members are divided by press-molding in divided units. Some share a mold (for example, see Patent Document 2).
JP 2005-53323 A JP 11-78961 A

  Press molding with a dedicated press die requires a large number of dies and increases the manufacturing cost. Press molding by division unit can realize optimum plate thickness setting according to each part, and even if the molds can be shared between the left and right side members, the number of molds is increased, and the members are divided and molded The assembly of the piece is necessary, and the manufacturing cost becomes high.

  The problem to be solved by the present invention is to reduce the manufacturing cost of the front side member by sharing the mold of the front side member corresponding to the vehicle length and having different lengths in the longitudinal direction of the vehicle body.

  A vehicle front side frame according to the present invention is a vehicle front side frame that extends in the longitudinal direction of a vehicle body, and has a collision crushing region at a front side of the vehicle body, and at least the vehicle body front side of the collision crushing region is the same. The cross-sectional shape.

  A method for manufacturing a vehicle front side frame according to the present invention is a method for manufacturing a vehicle front side frame extending in the longitudinal direction of a vehicle body. In the multi-product production in which at least the front side of the vehicle body has the same cross-sectional shape and the same cross-sectional shape portion of the collision crushing region has different longitudinal lengths depending on the vehicle length, the same cross-sectional shape portion Prepare a mold used for press molding of the front side frame having a longer length in the longitudinal direction of the vehicle body. The mold is divided into a front side frame having a long longitudinal length in the longitudinal direction of the vehicle body and a short front side frame of the same cross-sectional shape portion. It is characterized by being used for both press molding.

  The method for manufacturing a vehicle front side frame according to the present invention preferably uses a blank having the same plate thickness for the front side frame and the short front side frame having the same cross-sectional shape portion having a long front-rear direction length. A front side frame having the same cross-sectional shape in the longitudinal direction of the vehicle body is characterized in that a stiffener having higher strength and rigidity is attached and attached to a portion including the collision crushing region.

  According to the present invention, in the press molding of the front side frame, at least the front side of the vehicle body in the collision crushing region set at the front side of the vehicle body is set to the same cross-sectional shape, and the vehicle body longitudinal direction length of the same cross-sectional shape part is set. A mold used for press molding of the longer front side frame can be shared for press molding of the front side frame having a shorter length in the longitudinal direction of the vehicle body. As a result, the molds of the front side members having different lengths in the longitudinal direction of the vehicle body can be shared, and the manufacturing cost of the front side members can be reduced.

  Embodiments of a vehicle front side frame and a method for manufacturing the same according to the present invention will be described below with reference to FIGS.

  The vehicle body structure to which the vehicle front side frame of the present embodiment is applied, as shown in FIG. 1, is a left and right front side member 11 extending in the longitudinal direction of the vehicle body as a skeleton strength member of the front vehicle body. 12 and a front bumper beam 15 for connecting the extension members 13 and 14 joined to the front end portions of the front side members 11 and 12 to each other, and an engine room 16 is defined inside them.

  The left and right front side members 11 and 12 are fixedly joined to the front ends of the left and right side sill members 17 and 18 by the outriggers 19 and 20, respectively.

  The lower ends of the wheel house upper members 23 and 24 are joined to the outer sides of the front end portions of the left and right front side members 11 and 12 by connecting members 21 and 22, respectively. The lower ends of the left and right front side pillars 25 and 26 are joined to the upper ends of the wheel house lower upper members 23 and 24.

  Between the left and right front side members 11, 12 and the wheel house upper members 23, 24, the upper side is joined to the wheel house upper members 23, 25 and the lower side is joined to the front side frames 11, 12. Front wheel houses 27 and 28 are provided. Damper housings 29 and 30 are formed integrally with the front wheel houses 27 and 28.

  The left and right front side members 11 and 12 are each press-formed into a U-shaped groove-shaped cross section, and back plates 31 and 32 (see FIG. 4) are joined to the groove opening side of the groove-shaped cross section to form a box-shaped cross-sectional structure. It has a skeletal structure.

  2 shows the entire front side members 11 and 12 with the back plates 31 and 32 attached, and FIG. 3 shows the front side members 11 and 12 with the back plates 31 and 32 removed. Each of the stiffener parts is shown. In these drawings, the vertical line indicated by the symbol A is an assumed folding line (vertical folding line) of the front side frames 11 and 12 at the time of an offset collision, and from this, the front side of the vehicle body (in FIGS. 2 to 4). The right side as viewed) is a crushed area Ba at the time of collision.

  As shown in FIG. 3, a main stiffener 41 is overlapped and joined to the inner side surfaces of the standing wall portions 37 of the left and right front side members 11 and 12. The main stiffener 41 is made of, for example, high-strength steel, is long along the longitudinal direction of the front side frames 11 and 12, and the front end edge 42 is stepped in the longitudinal direction of the vehicle body.

  The front edge 42 of this step is at a position straddling the assumed folding line A in the longitudinal direction of the vehicle body, a lower region 42A located on the front side of the vehicle body from the assumed folding line A, and an upper region located on the rear side of the vehicle body from the assumed folding line A 42B.

  As shown in FIGS. 3 and 5, the front side members 11, 12 have auxiliary stiffeners 51 on the front side frames 11, 12 so as to straddle the front end edge 42 of the main stiffener 41 in the longitudinal direction of the vehicle body. The standing wall portion 37 and the main stiffener 41 are overlapped and joined. That is, the auxiliary stiffener 51 has a rectangular flat plate shape, the front side of the vehicle body is overlapped and joined to the standing wall portion 37 of the front side frames 11 and 12, and the rear side of the vehicle body is overlapped and joined to the main stiffener 41.

  The auxiliary stiffener 51 is made of high-tensile steel like the main stiffener 41, but the thickness of the auxiliary stiffener 51 is thinner than the thickness of the main stiffener 41, and a proof stress difference is given to the main stiffener 41. .

  At least the vehicle body front side of the collision crushing region Ba set in the vehicle body front side portion of the front side frames 11 and 12 is a U-shaped section 33 and 34 having the same cross-sectional shape.

  The front side frames 11 and 12 are manufactured by play molding using a metal mold, including the same cross-sectional shape portions 33 and 34. In various types of production in which the same cross-sectional shape portions 33 and 34 have different lengths in the longitudinal direction of the vehicle body according to the vehicle length, in this embodiment, the longitudinal lengths of the same cross-sectional shape portions 33 and 34 are short (Ca ) And long type (Cb), as shown in FIG. 7, press molding of the front side frames 11 and 12 having the same cross-sectional shape portion with the longer longitudinal direction of the vehicle body (Cb) A mold 100 for use in the above is prepared.

  The size of the press molding recess 101 of the mold 100 is adapted to the press molding of the front side frames 11 and 12 in which the same cross-sectional shape portions 33 and 34 are long in the longitudinal direction of the vehicle body (Cb). The length of the concave portion of the portion for forming the cross-sectional shape portions 33 and 34 is a length suitable for the long portion (Cb).

  As a result, the mold 100 is formed by pressing both the front side frames 11 and 12 (Ca) and the short (Ca) front side frames 11 and 12 having the same cross-sectional shape portions 33 and 34 in the longitudinal direction of the vehicle body. Can be used for both.

  In the press molding of the front side frames 11 and 12 with the same cross-sectional shape portions 33 and 34 using the mold 100 being short (Ca), an excess portion of (Ca-Cb) is generated in the press molding recess 101 of the mold 100. However, there is no problem such as deformation in the press molding of the front side frames 11 and 12.

  Thus, by sharing the mold 100 with the front side members 11 and 12 having different lengths in the longitudinal direction of the vehicle body, the manufacturing cost of the front side members 11 and 12 can be reduced.

  Since the front end side of the front side members 11 and 12 is only to extend the same cross section, the same extension members 13 and 14 and the front bumper beam 15 are connected to the front side members 11 and 12 having different lengths in the longitudinal direction of the vehicle body. The effect that it can be used is also acquired.

  In addition, the above-mentioned collision crushing area is set according to the vehicle body longitudinal direction length of the same cross-sectional shape parts 33 and 34, and when the same cross-sectional shape parts 33 and 34 are short (Ca), When the same cross-sectional shape portions 33 and 34 are long (Cb) in the collision crushed area Ba, the collision crushed area Bb is set.

  When the mold 100 is shared, the same cross-sectional shape parts 33 and 34 have the same plate thickness in the front side frames 11 and 12 where the longitudinal length of the vehicle body is long (Cb) and the short (Ca) front side frames 11 and 12. Use a blank.

  On the other hand, the main side stiffener 41 and the auxiliary stiffener 51 having the higher strength and rigidity as the front side frames 11 and 12 having the same cross-sectional shape portions 33 and 34 having longer longitudinal lengths in the vehicle body direction are collided. ).

  Accordingly, the strength of the front side frames 11 and 12 can be compensated by increasing the weight of the front side frames 11 and 12, and the front side frames 11 and 12 having the same cross-sectional shape portions 33 and 34 having a long longitudinal length in the vehicle body front and rear direction. However, the required strength can be secured.

  It should be noted that the strength and rigidity of the main stiffener 41 and the auxiliary stiffener 51 can be adjusted to required values depending on the material, plate thickness, etc. of these stiffeners.

1 is an overall perspective view showing one embodiment of a vehicle body structure of an automobile to which a vehicle front side frame according to the present invention is applied. It is a side view showing one embodiment of the front side frame for vehicles by the present invention. It is an expanded side view of the principal part of one embodiment of the front side frame for vehicles by the present invention. It is a perspective view showing one embodiment of the front side frame for vehicles by the present invention. It is an expansion perspective view which shows the stiffener structure applied to the front side frame for vehicles by this invention. It is a top view of the front side part of the front side frame for vehicles by the present invention. It is a schematic plan view of the metal mold | die used for implementation of the manufacturing method of the front side frame for vehicles by this invention.

Explanation of symbols

11, 12 Front side member 13, 14 Extension member 15 Front bumper beam 16 Engine room 17, 18 Side sill member 19, 20 Outrigger 21, 22 Connecting member 23, 24 Wheelhouse upper member 25, 26 Front side pillar 27, 28 Front Wheel house 29, 30 Damper housing 31, 32 Back plate 33, 34 Same cross-sectional shape part 41 Main stiffener 42 Front edge 51 Auxiliary stiffener

Claims (3)

A front side frame for a vehicle extending in the longitudinal direction of the vehicle body,
A vehicle front side frame having a crash crushing region at a front side of a vehicle body, wherein at least a vehicle front side of the crash crushing region has the same cross-sectional shape. A method for manufacturing a front side frame for a vehicle extending in a longitudinal direction of a vehicle body,
Using a mold, press-form at least the front side of the collision crushing region set in the front side of the vehicle body into the same cross-sectional shape,
For various types of production in which the longitudinal cross-sectional length of the same cross-sectional shape part of the collision crushing region varies depending on the vehicle length, for press molding of the front side frame having the longer longitudinal cross-sectional length of the same cross-sectional shape part. A vehicle front comprising: preparing a mold to be used, and using the mold for press molding of both a front side frame and a short front side frame having a long front-rear direction length of the same cross-sectional shape portion A method for manufacturing a side frame.   A front side frame in which the same cross-sectional shape part has a long front-rear direction length and a short front side frame uses a blank having the same thickness, and the same cross-sectional shape part has a long front-rear direction length in the front-rear direction. 3. The method of manufacturing a vehicle front side frame according to claim 2, wherein a stiffener having higher strength and rigidity is joined and attached to a portion including the collision crushing region.

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